The present invention finds applicability in the field of electrocardiograms; and more specifically placing leads on a patient prior to taking an electrocardiogram.
1. Background Information
Most 12-lead EKG requires specifically trained personnel to place nine separate electrodes that adhere to specific areas of the patient""s body. A wire to a monitor connects each electrode. Electrical activity of the heart is transformed into a wave form via a computer and displayed on a screen or recorded on graph paper in 12 different views or xe2x80x9cleadsxe2x80x9d. The leads are various combinations of the electrodes. An alarm system signals when a lead is missing or malfunctioning.
The placement of leads in a 12-lead EKG is described in U.S. Pat. No. 5,184,620 to Cudahy, the contents of which are incorporated herein in their entirety. The leads show views of the heart in two planes. The frontal plane view uses different combinations of electrodes L1, L2 and L3 to create six different leads. The horizontal plane view uses each of the precordial electrodes V 1-6 to create six different leads. Together, there are a total of twelve leads. This describes the routine 12-lead EKG most commonly used.
A standard 12-lead electrocardiogram (EKG) provides a comprehensive picture of the heart""s electrical activity. Each lead provides a different view.
The six limb leads originate from three electrodes placed on the patient""s arms and left leg. The limb electrodes are marked with abbreviations: LL (left leg), RA (right arm), and LA (left arm). They provide the basis for the three standard limb leads and the three augmented limb leads.
The three standard limb leads (I, II, and III) represent the difference in bipolar electrical potential between two of the limb electrodes, as follows: (one electrode is positive, one is negative)
lead I: right arm (xe2x88x92)/left arm (+)
lead II: right arm (xe2x88x92)/left leg (+)
lead III: left arm (xe2x88x92)/left leg (+)
The three argmented limb leads (AVR, AVL and AVF) use the same three electrodes as the standard limb leads I, II and Im to measure the unipolar electrical potential in one electrode in reference to the other two electrodes:
lead AVR: right arm (+) in reference to left arm (xe2x88x92), left leg (+)
lead AVL: left arm (+) in reference to right arm and left leg
lead AVF: left leg (+) in reference to left arm and right arm.
For a horizontal view from the heart to an electrode placed on the chest, one looks to the six precordial leads (V1 and through V6). For an accurate lead recording on the ECG, one needs to place the chest electrodes correctly. One starts by finding the proper landmarks for V1xe2x80x94fourth intercostal space, right sternal border-because this position will be your guide for placing the other chest electrodes.
To place the electrode for V1, one follows these steps:
First, palpate the jugular notch (a depression).
Move inferiorly and palpate the solid manubrium.
Continue to move inferiorly and feel the angle of Louis (sternal angle), which is at the top of the sternal body.
Directly to the right of the angle of Louis is the second right rib. Below the second right rib is the second intercostal space.
Move your fingers down, palpating the next two ribs. Below the fourth rib and to the right of the sternal body is the fourth intercostal space. Place the V1 electrode here.
Then place V2 through V6 as follows:
V2: fourth intercostal space, left sternal border
V3: midway between V2 and V4 
V4: fifth intercostal space, left midclavicular line
V5: same level as V4 at anterior axillary line
V6: same level as V4 at left midaxillary line.
The lead placement must be precise within a few centimeters, requiring knowledge and skill. The education and training of personnel is time consuming and expensive. The procedure may only be available where there are trained personnel. There is variability in placement between personnel and each new procedure, leading to variability in readings. The placement of each lead or electrode in the designated anatomical position often requires repeated attempts. This limits the use of the 12-lead EKG in emergency settings. Multiple pieces of equipment (electrodes, clips, wires, etc.) and connection sites carry the risk of damage, loss of improper use and the knowledge to detect and correct the problem. In addition, extra pieces of equipment must be available and functional in each setting used. The additional training and equipment add costs.
2. Prior Art Patents
Beitler (U.S. Pat. No. 5,782,238) discloses a flexible multiple electrode lead EKG device for patient-attachment. There are switches on the electrodes for activating the proper electrode. The device is weighted for attachment rather than through adhesion.
Wilk (U.S. Pat. No. 5,257,631) teaches an electrocardiographic device which is coextensive with the chest of the patient being tested. The device is weighted and attached by straps.
Cudahy (U.S. Pat. No. 5,184,620) teaches an electrode pad having a plurality of electrode sites. The electrode placement device is held in place by adhesive. The configuration of the Cudahy device does not allow for accurate placement of the device across the chest because of the lack of a visual guide relative to the body.
The following patents also show multiple electrode EKG devices for hooking a patient to an electrocardiograph instrument.
None of the prior art patents show the unique features of the electrode placement device as described by the herein disclosed invention.
The herein described invention is designed to facilitate electrode placement by eliminating single lead electrode placement habitually resorted to in the prior art.
The herein disclosed invention requires no special skill to use, thereby eliminating the cost of training personnel and eliminates the need for skilled personnel. This in turn allows the device to be used in a much wider variety of settings such as cardiac stress testing, operating rooms, radiological suites, in the field, ambulance, emergency rooms, catheterization laboratories, outlying facilities, doctors offices, geriatric centers, and other care provider settings. Variability in readings is largely minimized. There is a great decrease in time required to place the device, which allows for use in emergency settings. The number of parts and pieces of equipment are reduced and most are disposable. The design allows a cost savings as no material is wasted in construction of a triangle (e.g., a square or rectangle cut in half), as opposed to configurations currently in use. The choice of adapters (provided along with the device) allow the device to be universally used with almost any EKG machine. The device could be used as well with an electronic system which would allow for remote readings.
Described another way, the electrode placement device is to be used for taking an electrocardiogram and, preferably, has a triangular applicator to be applied to the chest of a patient prior to taking an electrocardiogram. The device is sized to fit the patient and the top portion of the device is straight across to ensure accurate placement of the device. The device is in the shape of a triangle and has electrodes placed therein. The device can be placed on the patient during an emergency situation and kept on that patient in the ambulance, in the emergency room, operating room and recovery room. The device can be described comprehensively as being a disposable electrode lead placement device intended to be applied by a doctor, nurse or technician to a patient""s chest for the purpose of facilitating EKG readings on the patient""s heart. One of the contacts or electrodes of the device is marked on the front portion of the device and clearly visible externally thereof, such that the doctor, nurse or technician may quickly position that one electrode at an approximately correct predetermined location on the patient""s chest and then align the straight top edge of the device substantially in a horizontal plane, such that the remaining contacts in the array of prepositioned contacts on the device are thereby disposed in a substantially correct alignment with respect to respective locations in the patient""s chest from which the EKG readings are to be taken. The disposable device has a plan outline which is substantially triangular and includes a right angle corner, and wherein a contact is disposed adjacent to the right angle corner.
The device is intended to be maintained on the patient""s chest for a time interval from an initial emergency situation through treatment until recovery, such that a datum is established for the patient, and such that any deviation from that datum may be quickly observed.
The device can be used in a method of obtaining early EKG readings from a patient in an emergency situation and thereafter taking periodic EKG readings on the patient and readily detecting any significant differences in the EKG readings indicative of a particular problem being experienced by the patient during diagnosis, treatment and recovery. This method includes the steps of providing a disposable device in a sterile package, the package providing indicia and instructions externally thereon, such that an emergency medical technician may quickly position the device on the patient""s chest in an approximately desired location. An adhesive is provided on the back portion of the device along with providing a peel-off protective layer for the device.
With the problems attendant to use of conventional electrodes, the herein disclosed invention has the following objectives:
to provide a device which makes placement of EKG electrodes simple and accurate.
to provide a relatively-inexpensive disposable device for use with an electrocardiogram (EKG) device which is inexpensive.
to produce an electrode placement EKG device which is easy to use.
to produce an electrode placement EKG device which requires no special training for use.
to provide an electrode placement EKG device with universal applicability.
to provide an electrode placement EKG which is xe2x80x9cfail safexe2x80x9d.
These and other objects of the present invention will become apparent from a reading of the specification taken in conjunction with the enclosed drawings.